Canopy recruitment in the beech (<Emphasis Type="Italic">Fagus engleriana</Emphasis>) forest of Mt. Shennongjia,Central China

A dendrochronological technique was used to investigate canopy recruitment of beech (Fagus engleriana Seem.) trees in western Hubei Province of Central China by identifying growth releases through gap formation. The results indicated that 83% and 17% of the canopy trees regenerate in gaps and the understory, respectively. Radial growth analyses demonstrated that there are three modes for beech regeneration and canopy recruitment: (1) gap origin without suppression; (2) gap origin with period(s) of suppression; and (3) understory origin. Multiple periods of release and suppression imply that beech regeneration and canopy recruitment are very sensitive to gap formation.     

Forest resources and environment in China

Covering a vast territory, China is rich in forest resources and diversified environments. The changes in forest resources have a direct bearing on environmental quality. This paper gives a detailed account of the dynamic change in forest resources in China, including the overall process of forest evolution, the status quo, and features of the existing forest resources and the development and use of major forest resources. In addition, it analyses the current situation of China’s environment and explores the main contributing factors based on the overall environmental situation. To achieve sustainable management of forest resources and improve the environment in China, the Chinese Government attaches great importance to the protection and development of forest resources as well as to environmental development and improvement. The paper gives an overview of current thinking for sustainable forest resource and environmental development in the future and highlights the current focus of efforts toward this objective.     

Relationships between larch growth and forest site factors

Dahurian larch (Larix gmelinii Rupr.) Rupr is one of the dominant species in both natural and man-made forests in northeast China. Effects of site factors, including topography, soil properties and nutrient elements (P, Ca, K, Mg, Mn, Zn, Cu, Ag, Co and Ni) on the growth of larch were analyzed in detail, qualitatively and quantitatively. The ordination technique was used to group the site factors and to classify sites for larch. Analysis indicated that height growth, diameter (DBH) and volume of the larch varied among site types and this will be of theoretical and practical significance in developing larch plantations.     

我国木材加工机械发展展望

根据木工机械制造业状况,从我国木工机械行业发展趋势、经营模式、走向世界的途径等方面进行分析,探讨重塑木工机械产品品牌对于促进我国成为木工机械行业全球车间的意义.     

中国竹子多样性及其利用评述

本文评述我国竹子种类、群落、遗传和利用等4个方面多样性，并探讨竹类资源多样性利用存在的问题及对策，为我国竹类资源多样性开发利用提供依据。     

北美浆果树种在中国西部地区引种效果及应用前景

中国西部地区水资源贫乏，生态环境极其脆弱，适合生长的造林树种十分稀少，为此近10a来引进了许多北美生态经济型灌木类浆果树种，以满足生态环境恢复和建设的需要。引种试验结果表明，多数树种适合在中国西部地区栽培，发展前景十分广阔，应尽快大面积推广。同时也指出了易出现的问题、解决方法及发展建议。     

Strategic Trend of Chinese Urban Forestry Development

1 STRATEGY BACKGROUND1.1 Quickening of Urbanization ProcessSince the reform and opening-up in China in 1978,economic community developed rapidly. By the endof 2003, GDP has exceeded $1 000 billion. With therapid development of Chinese economy, residentialmode focusing on rural population is now changing,urbanization process is quickening, traditional cityscale is expanding into metropolis (Tianjin, Xi’an,Chengdu, Chongqing, etc.) or super cities (Beijing,Shanghai, Guangzhou, etc.…     

东北蕨类植物区系特征与分区

东北蕨类植物计２４科５１属１４０余种、变种，是中国北方蕨类多样性最丰富的地区。根据属的现代地理分布，东北蕨类植物可划分成７种地理成分，其中以北温带成分和东亚成分所占比例最大，反映了本区系的温带性质。区系中包含了东北亚蕨类植物区系的２个特有属，３０个特有种，是东北亚蕨类植物区系的中心区域。本区系与周围蕨类植物区系存在着广泛而复杂的联系：与朝鲜的共有种多达１０４种，与日本的共有种达１００种，与俄罗斯远东的共有种为８１种，与华北地区的共有种７２种，与秦岭地区的共有种７０种，与蒙古的共有种５３种，与西伯利亚的共有种４６种，与北美洲及欧洲的共有种各为３９种。根据蕨类植物的分布特点和种类组成，将东北蕨类植物区系划分成４个区，即长白、大兴安岭、蒙古、华北蕨类植物区。长白区有蔬类植物１２４种，东北亚特有成分主要分布于本区，是东北蕨类植物区系的中心区域；华北区有蕨类植物８７种，喜温喜热成分较多，反映了东北蕨类植物一定的热带、亚热带亲缘；大兴安岭区有蕨类植物４３种；蒙古区有蕨类植物近３０种，多耐寒、耐旱种类。东北蕨类植物的垂直分布带谱是很明显的，以长白山为例，海拔５００ｍ以下为落叶林蕨类植物带，海拔５００—１０００ｍ为暗针叶林     

不同类型林分土壤微生物生理类群分析

本研究就三种不同处理林分土壤微生物生理类群的初步分析,表明杉木马尾松混交后有利于固氮微生物的生长,固氮微生物数量的增加,促进了混交林分生长;有利于氨化细菌的生长,氨化细菌数量的增加,又利于提高含氮有机物的分解和转化速率,从而提高混交林地土壤肥力;同时促进了纤维素分解菌的生长,利于有机物的转化和加快碳素循环速率,从而为植物生长提供更多的碳素和能源。因此,在混交林中杉木的平均胸径比对照提高24%,平均树高比对照提高21%;马尾松平均胸径比对照提高20%,平均树高比对照提高19%,可见营造杉、马混交林比纯林更具发展潜力,可实现树高、胸径积累的双赢。